The background description provided herein is for the purpose of generally presenting the context of the disclosure. Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art or suggestions of the prior art, by inclusion in this section.
Many mobile devices may be equipped with mechanical switches or buttons on the sides, sometimes along the metal band, to provide various control functions, such as power on/off, volume up/down, etc. Similarly, many modern mobile devices may be equipped with touch sensing technologies (e.g., virtual buttons of home, back, menu, etc.) in the front to provide various control functions. Capacitive sensing is a touch sensing technology based on capacitive coupling that may use human body capacitance as input.
Many mobile devices may use a metal band at the outside edges as a design feature to improve the durability and aesthetical value of the products. In many occasions, the metal band may be made as part of the wireless antenna system to improve wireless reception of the mobile device. However, existing touch sensor designs cannot be used for replacing mechanical switches on the sides of mobile devices, for example, due to the interference from the conductive metal band.